feat(hyprland): float+center Bluetooth + printer config dialogs

Conservative first cut of the floating-window audit (item 41): float and
center the two shipped, unambiguous config dialogs — blueman
(manager/adapters) and system-config-printer — alongside the mixer. Uses
(?i) class regexes tolerant of the XWayland `.…-wrapped` form, consistent
with the existing (?i) usage in this file.

Deliberately conservative: network is dmenu/nmtui (no GUI editor), and the
polkit prompt + GTK file portals are deferred because their window class
can't be verified headlessly — a guessed class is a dead rule. Those wait
for a hardware `hyprctl clients` read (queued).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

agent/BACKLOG.md

@@ -257,16 +257,20 @@ summer-day/summer-night) — all deliberately set `scrollbar { width:0 }`
 today, each needs a per-theme handle width/colour. Payoff is V3-only
 (rendering), so it wants a themed session, not a headless edit.
 
-### 41. Floating-window audit
-(Raised by Bernardo, 2026-07-07 — item 11.) Decide which windows should
-open floating by default (config dialogs, file-chooser portals,
-calculators, etc.) and add the `windowrule` float rules in
-`hyprland.nix`. Enables item 36b. Produce the list first, then the rules.
-_Note 2026-07-07:_ the **first** `windowrule` block now exists (added by
-item 35 — the mixer floats + centers), so the pattern + placement are
-set. 41 is now purely "broaden the set" — audit the template app suite,
-pick the dialog/utility classes, append rules. Still list-first
-(Bernardo's taste on what should float), so it wants his review.
+### 41. Floating-window audit — remaining (needs hardware class checks)
+(Raised by Bernardo, 2026-07-07 — item 11.) Broaden the `windowrule`
+float set beyond the conservative first cut.
+_Conservative cut shipped 2026-07-07 (iteration #63, on Bernardo's "take a
+conservative approach"):_ float + center the mixer (item 35), **blueman**
+(manager/adapters) and **system-config-printer** — the only shipped,
+unambiguous config dialogs whose classes are confident. **Remaining
+candidates, deliberately deferred because their window class can't be
+verified headlessly** (a guessed class = dead rule): the polkit auth
+prompt (hyprpolkitagent — no discoverable class in the package), GTK
+file-chooser portals (`xdg-desktop-portal-gtk`), and any pinentry dialog.
+Next slice: on hardware, run `hyprctl clients` while each is open, read
+the real `class`, then append rules. Also revisit whether blueman/s-c-p
+actually float once seen (regex tolerance for the `.…-wrapped` form).